Gas burner and control

ABSTRACT

A GAS BURNER HAVING TWO CONCENTRIC COMBUSTION SECTIONS WITH EACH COMBUSTION SECTION HAVING A SEPARATE GAS SUPPLY NOZZLE. A SINGLE GAS DISCHARGE CHAMBER FOR THE TWO SECTIONS IS LOCATED ABOVE THE BURNER AND IS CLOSED EXCEPT FOR A GAS DISCHARGE FLUE. HEAT IS TRANSMITTED BY INFRARED   RADIATION THROUGH A GLASS PLATE TOP AND BY CONDUCTION FROM THE GLASS PLATE.

Sept. 20,- 1971 E. A. REID, JR 3,605,612

GAS BURNER AND CONTROL 7 Filed Oct'. 20, 1969 2 Sheets-Sheet 1 v mvsmon. Edward A-. Reid Jk,

614123, Mot/viii I ATTORNEYS Sept. 20, 1971 E. A. REID, JR 3,606,612

GAS BURNER AND CONTROL Filed Oct. 20, 1969 2 Sheets-Sheet 2 5 I06 I |2,o0o

E I-IJ Z I I I I g 2 a 4 5 e 1 j CONTROL KNOB POSITION E O Fig.4

INVENTOR. Edward A. Reid J/fi BY (u/dis, lflonru's a Mel ATTORNEYS United States Patent 61 lice 3,606,612 Patented Sept. 20, 1971 3,606,612 GAS BURNER AND CONTROL Edward A. Reid, Jr., Columbus, Ohio, assignor to Columbia Gas System Service Corporation, New York, N.Y. Filed Oct. 20, 1969, Ser. No. 867,722 Int. Cl. F23q 9/08 US. Cl. 431-281 19 Claims ABSTRACT OF THE DISCLOSURE This invention relates to gas burners, particularly for cooking stoves and of the infrared type.

An object of this invention is to provide an infrared gas burner which has a high range in its heat output and which does not require air under substantial pressure. Another object is to provide an atmospheric infrared burner for flat top kitchen ranges which has improved qualities with regard to control. Another object is to provide infrared burners of the above types which are adaptable for wide ranges of uses and application. A further object is to provide for the above with an infrared burner (which will produce heating areas of diiferent sizes and a wide range in the amount of heat which is produced for unit areas. A further object is to provide an improved control system for burners of the types referred to above. These and other objects will be in part obvious and in part pointed out below.

In household gas ranges it is desirable to provide for modulation of the heat produced, i.e., modulating or reducing the intensity and heating effect of the gas flame. Also, it is desirable to provide heating areas of different sizes and yet permit wide variations in the heat intensities. In the copending application, Ser. No. 679,035 filed Oct. 30, 1967 now patent No. 3,470,862, there is disclosed a gas range with infrared burners and with a flat top of glass which transmits infrared rediant heat. The products of combustion from each of the burners pass through a discharge flue to the rear of the range. Each of the burners may be controlled to produce a relatively wide range of heat intensity and total heat. The present invention is related to that invention and permits a wider range in the amount of heat produced.

In the drawings:

FIG. 1 is a perspective view of one embodiment of the invention;

FIG. 2 is a perspective view of one of the burners in the embodiment of FIG. 1, with parts broken away and partially in section;

FIG. 3 is a schematic view of the gas valve assembly for the burner of FIG. 2; and

FIG. 4 is a graph showing the heat modulation which is provided in the burner of FIG. 2.

Referring to FIG. 1, a range has four burners 12, 14, 16 and 18 positioned within a frame 20. The top of the range is formed by a glass plate 26 which rests upon and seals the top of each of the four burners, thus providing a separate closed chamber 30 for the products of combustion from each burner. Air intake is provided by an open grill 22 on the front of the range. The products of combustion are exhausted from 'each chamber 30 through a flue 60 and a grill 24 in the rear. Gas control knobs 28 are located conveniently on the front of the range.

The four burners are identical in structure and in operation. Therefore, only burner 16 (will be described. Burner 16 has a center burner section 31 and an annular outer burner section 35 which surrounds the center burner section. The center and the outer burner sections have separate concentric plenum chambers 32 and 36, respectively, which are formed by a common flat bottom wall and two concentric cylindrical walls 44 and 46. The tops of the plenum chambers are closed by a screen 45 having a center disc portion 47 and an outer annular portion 48. Positioned in spaced relationship above screen 45 is a primary radiating screen 40 which has a center disc portion 50 forming the primary radiating surface for the center burner section, and an annular portion 52 forming the primary radiating surface for the outer burner sction 3 5. Immediately above screen 40 there is a single gas discharge chamber 54 for both burner sections which is formed by a cylindrical wall 56 and the coextensive area of the glass plate top 26. Plate 26 rests firmly against flange 58 on wall 56 to provide an adequate gas seal. Combustion products are discharged from chamber 54 through flue 60, one side wall of which is tangent to wall 56, and exit upwardly from the rear of the range at grill 24. The gas-air mixture is delivered tangentially to the two burner sections 32 and 36 by tubes 34 and 38, respectively, each of which has at its inlet end a Venturi type throat 37 and '39, respectively.

As will be explained below, and as represented schematically in FIG. 3, gas is supplied to the throated ends of tubes 34 and 38 by valves 64 and 84 having gas discharge nozzles positioned concentrically at the ends of the tubes. During operation the stream of gas from each of the valves is directed along the axis of its tube and causes the desired quantity of air to be entrained and flow with it through the tube throat. As the gas and air pass together through the throat restriction, the flow rate is accelerated and is then decelerated, and there is a mixing of the gas and air as the stream flows to the burner section. The delivery of the gas-air mixture tangentially to the plenum chamber of each burner section produces somewhat of a contracting spiral flow and provides an even distribution of the gas-air mixture and a substantially uniform pressure along the top of the plenum chamber. The gas-air mixture is ignited by a spark ignition unit (not shown) of known construction, and the primary radiating surfaces are heated, and the products of combustion pass into chamber 54. Infrared radiation is transmitted through plate 26 very efliciently so that the radiant heat passes from the primary radiating surfaces directly to a cooking utensil positioned on the plate above the burner. The disc portion of plate 26 directly above the burner is also heated by the products of combustion and it transmits heat to the utensil by conduction and convection. The products of combustion flow tangentially from chamber 54 through flue and are discharged upwardly through grill 24.

As will be discussed more fully below, it is desirable to modulate the heating effect of the burner. Hence, the amount of gas supplied to the burner sections can be reduced. In the illustrative embodiment, both burner sections are turned on initially and the heating is modulated by first producing a gradual reduction in the supply of gas to the outer burner section 35. The outer burner section is then turned off completely leaving the center burner section operating at its maximum heat level. The center burner section is then modulated to a minimum heating level. However, throughout the entireoperating range, the burner produces infrared radiation and continues to deliver heat to the utensil on top of plate 26 in an efiicient manner.

Referring now to FIG. 3, gas is supplied to the throated tube ends 37 and 39, respectively, by a pair of valves 64 and 84 which have discharge nozzles 70 and 90, respectively, concentrically positioned with respect to their tubes. Valves 64 and 84 have: the respective valve bodies 65 and 85; vale plugs 66 and 86 rotatably mounted in the valve bodies; valve stems 80 and 100 which are fixed to their valve plugs for rotation thereof; gas inlet nipples or connections 72 and 92 which are connected to the gas supply line (not shown); nozzle pins 68 and 88 which are mechanically connected to rotate with their valve plugs which have enlarged central portions 67 and 87 which are threaded in the valve bodies in the manner discussed below; and a valve operating means comprising the knob 28 on stem 100, a drive belt 102 mounted to rotate stem 80 with stem 100 so that the valve plugs 66 and 86 move together and always have the same angular relationship.

Thevalve plugs have central bores to which the gas passes through radial bores 74 and 94, when the valves are open, from the inlet ports 73 and 93 of nipples 72 and 92, respectively. The nozzle pins 68 and 88 have slots 69 and 89, respectively, which provide passageways for the gas to flow from the central bores in the valve plugs 66 and 86 to the nozzle chambers 71 and 91, respectively. Hence, when radial bore 74 is in alignment with the inlet port 73, gas flows freely through bore 74 and the center bore in the valve body and slots 69 to chamber 71, and thence from chamber 71 through the annular nozzle Opening around the pointed conical end of pin 68.

As indicated above, pin '68 is threadably mounted so that the pin may be rotated to adjust the axial position of its conical end with respect to the nozzle opening. At the time of installation the pin position may be adjusted to satisfy the particular requirements for the burner. However, the pin is also mechanically connected at its left-hand triangular end portion 75 with a mated socket in the valve plug so that the pin is rotated when the valve plug is turned. As will be explained more fully below, the valve plug is turned to reduce the amount of gas being supplied to its burner section. That turning movement of the valve body also turns pin 68 so as to screw it to the right and project its conical end further into the nozzle opening. That movement reduces the size of the nozzle orifice so as to restrict the flow and maintain an acceptable velocity for the gas flowing from the nozzle into the throated end of tube 34. Valve 84 operates in a similar manner and certain of the parts have been given numerals, the last digits of which are the same as those of valve 64.

Extending radially from bore 94 is a tapered slot 98 the cross-section of which is reduced in the direction from bore 94 to its remote end, the reduced cross-section being the result of reduced depth. Hence, as represented in FIG. 3, when knob 28 is turned counter-clockwise bores 74 and 94- are first moved into alignment with their respective inlet ports so that the full supply of gas flows through the valves, and the burner is ignited. When the counter-clockwise movement of knob 28 is continued, bore 94 moves past its port 93 and the tapered slot 98 moves into alignment with the port. Slot 98 produces a restriction in the flow of gas and as the knob is turned further slot 98 moves past port 93 so that the valve plug closes the end of port 93 and the valve is closed. Valve 64 has a similar feature with a radial bore 74 and a tapered slot 78. However, tapered slot 78 is spaced arcnately from radial 'bore 74, and there is a constant depth slot 76 extending between radial bore 74 and tapered slot 78. Slot 76 is of substantially the same crosssectional area as bore 74, and it extends arcnately of its valve body the length of tapered slot 98 of valve 84.

When knob 28 is turned as explained above, valve 64 is opened simultaneously with valve 84 by virtue of radial bore 74 moving into alignment with port 73. Upon further turning of knob 28, as explained above, so as to reduce the amount of gas passing through valve 84, the constant depth slot 76 is positioned in alignment with port 73 so that the unobstructed stream of gas flows from port 73 through slot 76 to bore 74 and there is no reduction in the fiow of gas through valve 64. However, when knob 28 is turned sufficiently to move tapered slot 98 of valve 84 beyond port 93 and shut off the fiow of gas through valve 84, tapered slot 78 of valve 64 is positioned at port 73. Hence, further turning of knob 28 gradually reduces the flow of gas through valve 64 and there is a stop at the minimum heating rate or level. It is thus seen that the first turning movement of knob 28 opens both valves but that further turning first gradually reduces the flow of gas through valve 84 while maintaining the maximum flow through valve 64. When the flow of gas through valve 84 is completely stopped there is then a gradual reduction of flow through valve 64. The burner is turned off by turning valve 28 clockwise back to its original position.

As explained above the turning of each of the valve bodies also turns its pin and advances the conical end of the pin into its nozzle opening. That reduces the size of the orifice and maintains an acceptable velocity for the jet of gas. Therefore, gas output from each valve is controlled at two points within the valve. First, the incoming gas is restricted at the inlet port by an arrangement of slots having varied depths. Next, the gas is controlled at the valve outlet nozzle by restriction in orifice size as the valve pin is advanced. In that manner, the jet of gas always entrains the desirable amount of air and causes the desired flow of the gas-air mixture into the burner section. During modulation of each burner section the gas-air mixture and the rate of gas flow are such as to continue producing infrared radiation at an efiicient rate.

With the preceding operation of the two valves, the sequence of performance is to first provide maximum or full burner heating. Thereafter, the center burner section continues to produce maximum heat while the heating by the outer burner section is gradually reduced to a minimum and then extinguished. Next, the inner burner section is modulated to its minimum heat output. The graph in FIG. 4 shows how this modulation procedure affects total heat output of the burner in terms of B.t.u.s per hour. The illustrative maximum heat output per hour is 12,000 B.t.u.s at 106, and it is reduced along line 108 to a value of 7000 B.t.u.s at 110, where the outer burner section is turned off. The heating then drops to 3000 B.t.u.s per hour at 112 and is reduced along line 114 to the minimum of the order of 1500 B.t.u.s per hour.

It should be noted that other sequences of burner operation and modulation can be utilized and that other valve arrangements can be used to control the gas flow. Each 'valve maintains the desired rate of gas and air flow into its burner section while providing sufficient pressure to prevent backflow into one section even at its minimum heat setting. The feature of modulating the outer burner section heat While maintaining maximum heat in the smaller inner burner section gives special advantages in the arrangement of the illustrative embodiment. This ensures complete exhaustion of combustion products through the flue, thus eliminating backflow even when the outer burner section is turned off. Since both burner sections are at maximum output when first turned on, a flow pat tern is established through the flue which continues even after the heat is reduced. The flue is adequately designed to carry away the maximum amount of combustion products that can be produced.

What is claimed is:

1. In a gas range having a horizontal air chamber within which there is air and throughout which such air may pass, a gas burner unit which burns fuel mixtures comprising fuel gas and air and which has means forming a plenum chamber section for the fuel mixture and a hot gas chamber for the products of combustion, said plenum chamber section having a central plenum chamber and an annular plenum chamber surrounding said central plenum chamber, burner element means positioned between said plenum chamber section and said hot gas chamber and forming the tops of said plenum chambers and the bottom of said hot gas chamber, cover plate means for transmitting infrared radiation and conductive heat and having a bottom surface forming the top of said hot gas chamber and confining the products of combustion, a pair of fuel mixture supply ducts having their delivery ends operably associated respectively with said central plenum chamber and annular plenum chamber to deliver separate supplies of fuel mixtures thereto and each having its other end adapted to receive air from said air chamber, means for projecting a jet of fuel gas into the said other end of each of said ducts and inducing a flow of air into said ducts 'With the fuel gas, and a hot gas discharge passageway having a gas-receiving relation end connected to said hot gas chamber and its other end extending therefrom to discharge the products of combustion.

2. The gas range as defined in claim 1 wherein said fuel mixture supply ducts are tangentially attached to their associated plenums whereby the air-fuel gas mixture within the respective plenums is caused to flow in a substantially circular pattern to produce an even distribution and complete mixing of the fuel gas and air.

3. The gas range as defined in claim 1 wherein said hot gas discharge passage is tangentially attached to said hot gas chamber and is open to atmosphere at its discharge end and is associated with a discharge opening from said air chamber whereby air flow is enhanced by convection.

4. The gas range as defined in claim 1 wherein said jet projecting means comprises a pair of operably connected valve means, each valve means including a fuel gas discharge nozzle associated with the free end of one of said ducts, each of said nozzles discharging fuel gas into its duct to cause a jet effect at the free end thereof to induce a flow of ambient air into the duct, and wherein said valve means includes means to modulate fuel gas flow to said nozzles.

5. The gas range as defined in claim 4 wherein each of said valve means includes a valve body having an inlet port adapted to be connected to a supply of fuel gas, a plug within said body operable to modulate fuel gas flow from the inlet port to the nozzle, and means for operably connecting the plugs in said valve together.

6. The gas range as defined in claim 5 wherein each of said valve bodies is a -generally cylindrical longitudinal- 1y extending member having its associated nozzle on one end thereof and each of said plugs constitutes a rotatable cylindrical member having an axial bore for communicating with its associated nozzle and inlet port and adapted to modulate gas flow therethrough.

7. The gas range as defined in claim 6 wherein each of said plugs includes a radially extending bore having one end adapted to be operably associated with said inlet port and its other end communicating with said axial bore, the plug modulating flow to said annular plenum including a tapered circumferential groove adjacent its radial bore and the plug modulating flow to said central plenum including a groove adjacent its radial bore having a first constant area section and a second tapered section, each section being substantially equal in length to said firstmentioned groove, to provide for gas modulation in the burner as the valves are rotated and the grooves are moved into communication with their respective fuel gas inlet ports whereby during the initial modulation phase a declining fuel gas-air mixture volume is provided to the annular plenum and a constant volume of fuel gas-air mixture is provided to the central plenum and during the final phase of gas modulation no fuel gas-air mixture is provided to the annular plenum while a declining volume is provided to the central plenum.

8. A gas burner of the infrared radiation type having a primary radiation surface and formed by a plurality of burner sections with each section having a separate plenum chamber positioned below said radiation surface with each said plenum chamber having a separate air-fuel gas mixture supply, a hot gas chamber above said radiating surface and communicating through said surface with said plenum chambers for receiving the products of combustion from said plenum chambers, means for discharging gases from the side of said chamber, a plurality of air-fuel gas supply assemblies comprising one such assembly for each of said burner sections, each of said air-fuel gas supply assemblies comprising a gas valve and means to discharge a jet of gas therefrom, each said plenum chamber including an air-fuel gas supply duct, each of said supply ducts and said air-fuel gas supply assemblies being so constructed and related such that a jet of gas entrains and carries with it into said duct and into its associated plenum chamber a desired amount of air to support combustion of the fuel gas within said associated plenum chamber and wherein said air-fuel gas supply assemblies have their valves constructed so that the amount of fuel gas flowing therethrough may be modulated by means to produce a restriction in the cross-sectional area through which the jet of fuel gas is discharged whereby a desirable rate of fuel gas flow is maintained at reduced rates of flow through the valve.

9. A gas burner as defined in claim 8 wherein the airfuel gas supply assemblies to each said plurality of plenum chambers include operative means for modulating the supply of air and fuel gas by modulating the supply of air and fuel gas to a selected burner section from a maximum to a minimum while maintaining maximum flow in the other of said plurality of burner sections and then to modulate the supply of air and fuel gas to another of said burner sections from a maximum to a minimum.

10. A gas burner as defined in claim 9 wherein said plurality of air-fuel gas supply assemblies are interconnected and said means to modulate the supply of air and fuel gas to said plurality of burner sections comprises a single operative means.

11. A gas burner as defined in claim 10 wherein said plurality of burner sections comprise a first central burner section and an annular section concentric therewith.

12. In a gas burner including inner and outer burner sections, first and second fuel supply ducts, each duct having a fuel discharge end and a free end which is open to ambient air, the fuel discharge end of said first duct being tangentially attached to said outer burner and the fuel discharge end of said second duct being tangentially attached to said inner burner, first fuel modulation means associated with the free end of said first duct and second fuel modulation means associated with the free end of said second duct for modulating the flow of fuel gas from a supply source to said ducts and the respective burners in a two-phase distribution, said fuel gas modulation means being operably interconnected for operation in unison.

13. The burner as defined in claim 12 wherein the fuel gas modulation means comprise first and second valve means for controlling the rate of fuel gas flow from said source and for maintaining sufiicient pressure within the burner to prevent backflow through the entire range of modulation.

14. The burner as defined in claim 13 wherein each of said valve means includes a valve plug to control the flow of fuel gas from the source into the valve and a discharge nozzle having a tapered needle valve therein adapted to control the rate of discharge of fuel gas from the valve to its associated fuel supply duct whereby sufficient pressure is maintained within the burner to prevent backflow within the range of modulation.

15. The burner as defined in claim 14 wherein the valve plug of said first valve means includes means for supplying a decreasing flow of fuel gas to its respective burner section during the first phase of distribution to the outer burner section and the valve plug of said second valve means includes means for supplying a constant flow of fuel gas to the inner burner section during said first phase and a decreasing flow during the second phase whereby in the first phase of fuel gas distribution the inner burner receives a constant full supply of fuel gas as the supply of the outer burner is decreased and in the second phase the supply of fuel gas to the inner burner is decreased and no fuel gas is supplied to the outer burner.

16. The burner as defined. in claim 15 including a hot gas discharge duct operably associated with the inner and outer burners for the removal of hot gases therefrom.

17. A dual gas burner assembly comprising a gas burner having an inner burner section and an outer annular burner section, a pair of air-fuel gas supply ducts each having a receiving end and a discharge end, each of said burner sections having the discharge end of one of said ducts communicating therewith for receiving an air-fuel gas mixture tangentially from said duct whereby a generally circular flow of air-fuel gas mixture is created in a plenum chamber associated with each said burner section to properly mix and uniformly distribute the air and fuel gas, a radiating surface above said plenum chambers adapted to produce infrared radiation, a gas discharge chamber above said radiating surface and communicating with the burner sections for receiving the products of combustion, means for transmitting radiant and conductive heat mounted on said gas discharge chamber and for preventing escape of hot gases therefrom, and gas discharge means having one end tangentially communicating with the hot gas chamber to remove hot gases therefrom by convection.

18. The assembly as defined in claim 17 including a valve means associated with each of said ducts for modulating fuel gas flow from a fuel gas source to the burner, each of said valve means including a fuel gas discharge nozzle adjacent the fuel gas receiving end of its associated duct for injecting the fuel gas into the duct and to provide a jet effect to draw a desired quantity of air into the duct with the fuel gas.

19. The assembly as defined in claim 18 wherein said valve means are operably interconnected by simultaneous operation and each valve includes a valve plug adapted to modulate the quantity of fuel gas admitted into the valve and a needle valve Within its nozzle operably connected to said plug to modulate the fuel gas flow rate into the receiving end of its associated duct as the quantity of fuel gas admitted into the valve is modulated whereby the jet effect of the nozzle is varied to maintain the desired fuel gas rate into the burners and suificient pressure within the assembly to prevent backflow.

References Cited UNITED STATES PATENTS 1,664,508 4/1928 Harper 431-280 1,839,366 l/l932 Alig 239559 2,963,042 12/1960 Dolby et al 137628 3,077,922 2/1963 Soucie 431284X 3,'402,739 9/1968 Kass 137-628 CARROLL B. DORITY, JR., Primary Examiner US. Cl. X.R. 

